Tibial tubercule osteotomy

ABSTRACT

Patient-specific guides for a tibial tubercle osteotomy are provided. The guides include a guide body defining a portion with a bone-engaging surface that conforms as a negative surface to a corresponding surface of a specific patient&#39;s tibia, and a guide portion that guides a surgical instrument to a specific location on the specific patient&#39;s tibia, wherein the bone-engaging surface and guide portion are configured during a pre-operative planning stage. Methods for performing a tibial tubercle osteotomy with the patient-specific guides are also provided.

RELATED APPLICATIONS

This application is a divisional application and claims the benefit of priority to U.S. application Ser. No. 14/500,019, filed Sep. 29, 2014, the content of which is incorporated herein by reference in its entirety.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

A tibial tubercle osteotomy is a surgical procedure which is performed to treat patellofemoral conditions, such as patellar instability, patellofemoral pain and chondrosis, and osteoarthritis. Such an osteotomy is typically performed when nonoperative measures, such as physical therapy, have failed. During a tibial tubercle osteotomy an incision is made in the anterior of a patient's leg just inferior to the patella, and a proximal and anterior portion of a tibia is partially resected to generate a tubercle flap. The tubercle flap is then repositioned in anterior and medial-lateral directions and held in place with screws. Typically, a tibial tubercle osteotomy results in anteromedialization (AMZ) of the tubercle. This repositioning alters the position of the patella in a patient to remove a pain-causing load, resulting in alleviation of a patellofemoral condition characterized by malalignment of the patella relative to asymptomatic individuals.

Many tibial tubercle osteotomies are performed with the aid of commercially available osteotomy systems. However, these systems generally comprise multiple units that are complicated to use. Moreover, the commercially available systems are mass produced, and are not tailored to a specific patient's anatomy. Therefore, there remains a need to develop new guide systems that are easier to use than currently available systems, and that are custom manufactured to match the anatomy of a specific patient.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

The present teachings provide a patient-specific guide for a tibial osteotomy. The guide includes a guide body defining a portion with a bone-engaging surface that conforms as a negative surface to a corresponding surface of a specific patient's tibia, and a guide portion that guides a surgical instrument to a specific location on the specific patient's tibia, wherein the bone-engaging surface and guide portion are configured during a pre-operative planning stage.

The present teachings also provide a patient-specific guide for a tibial osteotomy that includes a guide body defining a portion with a bone-engaging surface configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's tibia; and a plurality of apertures positioned in a straight line that defines a predetermined angle relative to a proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy. The plurality of apertures are configured to guide the insertion of a plurality of pins into the tibial. The plurality of apertures have a diameter that is larger than the diameter of the pins, which allows for the guide to be removed while leaving the pins in the tibia. The pins are used as a saw guide for resecting the specific-patient's tibia.

The present teachings further provide for a patient-specific guide for a tibial osteotomy that includes a guide body that defines: (a) a portion with a bone-engaging surface, wherein the bone-engaging surface is configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's tibia; (b) a first planar slot oriented at a first predetermined angle and at a first predetermined position relative to a proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy; (c) a second planar slot oriented at a second predetermined angle and at a second predetermined position relative to the proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy; and (d) a plurality of apertures. The plurality of apertures are configured to accept pins for removeably anchoring the guide to the specific patient's tibia.

Additionally, the present teachings provide a method for performing a tibial tubercle osteotomy on a patient's tibia. The method includes positioning a patient-specific guide on the patient's tibia, wherein the guide comprises a guide body defining a portion with a bone-engaging surface configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of the patient's tibia, and a plurality of apertures; inserting a plurality of pins through the apertures and into the patient's tibia; removing the guide; and resecting the tibia by using the pins inserted into the tibia as a saw guide and sawing the tibia adjacent to the pins from pin to pin to generate a tubercle flap adjacent to a resected surface of the tibia. The method also includes repositioning the tubercle flap in an anterior direction or in both anterior and medial-lateral directions to form a gap between the tubercle flap and the resected surface of the tibia; and implanting a wedge in the gap, wherein the wedge has a predetermined shape configured during the pre-operative planning stage and wherein the wedge is composed of a material that promotes bone in-growth.

Further, the present teachings provide a method for performing a tibial tubercle osteotomy on a patient's tibia. The method includes positioning a patient-specific guide on the patient's tibia, wherein the guide includes: (i) a portion with a bone-engaging surface, wherein the bone-engaging surface is configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's tibia; (ii) a first planar slot oriented at a first predetermined angle and at a first predetermined position relative to a proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy, wherein the first planar slot defined by the guide body has a distal end and a proximal end, and wherein the guide body further defines a circular slot in communication with the first distal end; (iii) a second planar slot oriented at a second predetermined angle and at a second predetermined position relative to the proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy; and (iv) a plurality of apertures. The method also includes anchoring the guide to the patient's tibia by inserting pins through the apertures; inserting a drill bit through the circular slot and drilling a hole through the tibia; inserting a saw blade through the first slot and resecting a first cut from the hole to the proximal end; inserting the saw blade through the second slot and resecting a second cut; removing the pins and the guide; and further resecting the tibia to connect the first cut and the second cut, and to connect the second cut to a surface of the tibia to form a tubercle flap adjacent to a resected surface of the tibia.

The present teachings additionally provide a surgical kit that includes a patient-specific guide having a guide body defining a portion with a bone-engaging surface that conforms as a negative surface to a corresponding surface of a specific patient's tibia, and a guide portion that guides a surgical instrument to a specific location on the specific patient's tibia, wherein the bone-engaging surface and guide portion are configured during a pre-operative planning stage; a patient-specific implantable wedge with a predetermined shape, wherein the wedge is configured during the pre-operative planning stage; and a plurality of pins.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a schematic illustration of a first patient-specific guide positioned relative to a tibia;

FIG. 2 is a schematic illustration of a second embodiment of the first patient-specific guide positioned relative to a tibia;

FIG. 3 is a schematic illustration of the first patient-specific guide positioned relative to the tibia, with pins inserted into the tibia;

FIG. 4 is a schematic illustration of planes cut through a tibia along the pins positioned with the use of the first patient-specific guide to generate a tubercle flap;

FIG. 5 is a schematic illustration of a repositioned tubercle flap generated with the use of the first patient-specific guide;

FIG. 6A is a schematic illustration of a first patient-specific implant;

FIG. 6B is a schematic illustration of a second patient-specific implant;

FIG. 7 is a schematic illustration of the patient-specific implant inserted into a gap generated in a tibia with the use of the first patient-specific guide;

FIG. 8 is a schematic illustration of a second patient-specific guide positioned relative to a tibia;

FIG. 9 is a schematic illustration of planes cut through a tibia with the use of the second patient-specific guide to generate a tubercle flap;

FIG. 10 is a schematic illustration of a repositioned tubercle flap generated with the use of the second patient-specific guide; and

FIG. 11 is a schematic illustration of the patient-specific implant inserted into a gap generated in a tibia with the use of the second patient-specific guide.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.

The present teachings generally provide patient-specific tibial tubercle osteotomy guides that include a guide body defining a portion with a bone-engaging surface that conforms as a negative surface to a corresponding surface of a specific patient's tibia about the patient's tibial tubercle, and a guide portion that guides a surgical instrument to a specific location on the specific patient's tibia, wherein the bone-engaging surface and guide portion are configured during a pre-operative planning stage, in which a medical professional determines the location of a tibial tubercle osteotomy and amount of correction needed. In various embodiments, the guide body further defines a soft tissue engaging surface, wherein the soft tissue-engaging surface is configured during the pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's soft tissue. The soft tissue can be the patient's medial collateral ligament, lateral cruciate ligament, or patellar tendon. In other embodiments, the guide body defines a surface that allows for clearance of soft tissue.

In one embodiment, the guide portion comprises a plurality of apertures defined by the guide body. The plurality of apertures are configured to guide pins to the specific-patient's tibia, wherein the pins are used as a saw guide for resecting the specific-patient's tibia. The plurality of apertures are positioned in three straight lines that define three predetermined angles relative to a proximal-distal axis of the patient's tibia that are selected during the pre-operative planning stage of the tibial osteotomy.

In another embodiment, the guide portion comprises a first planar slot defined by the guide body oriented at a first predetermined angle and at a first predetermined position relative to a proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy; and a second planar slot defined by the guide body oriented at a second predetermined angle and at a second predetermined position relative to the proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy. The first planar slot defined by the guide body has a distal end and a proximal end, wherein the guide body further defines a circular slot in communication with the first distal end.

The patient-specific alignment guides can be used either with conventional or patient-specific implant components prepared with computer-assisted image methods. Computer modeling for obtaining three dimensional images of the patient's anatomy using x-ray, MRI or CT scans of the patient's anatomy, the patient specific prosthesis components, and the patient-specific guides can be provided by various CAD programs and/or software available, for example, by Materialise USA, Plymouth, Mich. The guide will allow a surgeon to precisely cut an osteotomy, which ensures that an implant will match the native bone anatomy and provide the proper amount of adjustment.

The patient-specific alignment guides and associated patient-specific implants disclosed herein can be generally formed using computer modeling based on the patient's 3-D anatomic image generated from image scans. The patient-specific alignment guides can have a three-dimensional patient-specific engagement surface that is made to conformingly contact, mate with, and match a three-dimensional image of the patient's bone surface (selectively with or without soft tissue), by the computer methods discussed above. The patient-specific alignment guides can include custom-made guiding formations, such as, for example, guiding bores or guiding apertures, cannulated guiding extensions or receptacles that can be used for supporting or guiding other instruments, such as drill guides, reamers, cutters, and cutting guides or for inserting pins or other fasteners according to a surgeon-approved pre-operative plan.

In various embodiments, the patient-specific alignment guide can include one or more patient-specific cutting guides for receiving and guiding a cutting blade at corresponding patient-specific cutting plane orientations relative to a selected anatomic axis for the specific patient. The patient-specific alignment guides can also include guiding formations for guiding the implantation of patient-specific or off-the-shelf implants associated with the osteotomy procedure, such as implantable wedges and implantable fixation plates. The geometry, shape and orientation of the various features of the patient-specific alignment guide, as well as various patient-specific implants and other patient-specific tools can be determined during the pre-operative planning stage of the procedure in connection with the computer-assisted modeling of the patient's anatomy. During the pre-operative planning stage, patient-specific alignment guides, implants and other tools, can be designed and manufactured for a specific patient with input from a surgeon or other professional associated with the surgical procedure, as described in U.S. Pat. No. 8,632,547, issued on Jan. 21, 2014 to Maxson et al., U.S. Pat. No. 8,241,293, issued on Aug. 14, 2012 to Stone et al., and U.S. application Ser. No. 14/262,105 to Eash, filed on Apr. 25, 2014, all of which are incorporated herein by reference.

In the following discussion, the terms “patient-specific”, “custom-made” or “customized” are defined to apply to components, including tools, implants, portions or combinations thereof, which include certain geometric features, including surfaces, curves, or other lines, and which are made to closely conform as mirror-images or negatives of corresponding geometric features of a patient's anatomy during a pre-operative planning stage based on 3-D computer images of the corresponding anatomy reconstructed from image scans of the patient by computer imaging methods. Further, patient-specific guiding features, such as, guiding apertures and guiding slots, or other holes or openings that are included in alignment guides or in implants are defined as features that are made to have positions, orientations, dimensions, shapes and/or define cutting planes specific to the particular patient's anatomy based on the computer-assisted pre-operative plan associated with the patient.

The current technology provides a patient-specific tibial osteotomy guide 100 as shown in FIG. 1. The guide 100 comprises a guide body 102 that defines a portion with a bone-engaging surface 103 configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's tibia 104. As shown in FIG. 1, the guide 100 is positioned on the specific patient's tibia 104 about a tubercle 108 on a medial face of the tibia 104. In other embodiments, the guide 100 can be configured to be positioned on a lateral face of the specific patient's tibia 104. The bone engaging surface 103 is custom made during the preoperative planning stage to match a specific patient's anatomy and allows for placement of the guide 100 at a specific location at a proximal portion 106 of the patient's tibia 104. Typically, the guide 100 is configured to fit on and nest with only one position on the specific patient's tibia 104 at, around, or near the tubercle 108, which is to be repositioned during an osteotomy.

In some embodiments, the guide body 102 also defines a soft tissue-clearing portion 109 that allows for clearance of soft tissue, such as ligaments and tendons. The soft tissue-clearing portion 109 has an outer convex surface and an inner concave surface, wherein the inner concave surface provides a recess for accommodating soft tissue. As shown in FIG. 1, the soft tissue-clearing portion 109 accommodates the patient's patellar tendon 111. However, in various embodiments, the tissue-clearing portion 109 accommodates a medial collateral ligament (MCL) 113 or a lateral cruciate ligament (LCL, not shown). In this regard, the bone-engaging surface 103 mates with and conforms to a specific boney region of the tibia 104, and the patellar soft tissue-clearing portion 109 allows for the guide to simultaneously be placed about the patient's soft tissue, such as the patellar tendon 111. In other embodiments, the guide 100 comprises a plurality of tissue-clearing portions 109 for simultaneously accommodating the LCL and patellar tendon, or MCL and patellar tendon.

In additional embodiments, the guide body 102 further defines a soft tissue engaging surface 109′, wherein the soft tissue-engaging surface 109′ is configured during the pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's soft tissue at, around, or near the tubercle 108. The soft tissue can be, for example, the patient's MCL, LCL, or patellar tendon. In various embodiments, the guide 100 comprises a plurality of soft tissue engaging surfaces 109′ for simultaneously accommodating the LCL and patellar tendon, or MCL and patellar tendon. In other embodiments, the guide 100 has both a soft tissue-clearing portion 109 and a soft tissue engaging surface 109′.

The guide body 102 further defines a first plurality of apertures 110 positioned along a first straight line 112 that defines a first predetermined angle θ₁ relative to a proximal-distal axis 114 of the specific patient's tibia 104. The first straight line 112 is selected during the pre-operative planning stage of the tibial osteotomy. In many embodiments, a second plurality of apertures 116 is positioned along a second straight line 118 that defines a second predetermined angle θ₂ relative to the proximal-distal axis 114 of the specific patient's tibia 104 that is selected during the pre-operative planning stage of the tibial osteotomy, wherein the second line 118 intersects the first line 112. In yet other embodiments, a third plurality of apertures 120 is positioned along a third straight line 122 that defines a third predetermined angle θ₃ relative to the proximal-distal axis 114 of the specific patient's tibia 104 that is selected during the pre-operative planning stage of the tibial osteotomy, wherein the third line 122 intersects the second line 118.

The first, second, and third plurality of apertures 110, 116, 120 are configured to guide a plurality of pins 124 to the tibia 104 for insertion. The plurality of apertures 110, 116, 120 have a diameter D₁ and the pins 124 have a diameter D₂, wherein D₁ is larger than D₂. Because the apertures 110, 116, 120 have a larger diameter than the pins 124, the guide 100 can be removed from the tibia 104 by simply sliding the guide 100 off from the implanted pins 124. When the guide 100 is removed, the pins 124 provide a saw guide for resecting planes in the tibia 104 adjacent to the pins 124, from pin 124 to pin 124, to generate a tubercle flap 132 as shown in FIGS. 3, 4, and 6. Accordingly, the saw guide is adjacent to the pins 124 and matches the lines 112, 118, 122, configured during the preoperative planning stage. In other words, the pins 124 give visual indicia to a physician for making three intersecting planar cuts through the tibia 104.

As shown in FIG. 2, in various embodiments, the present technology provides for a bifurcated patient-specific alignment guide 150 comprising a first guide half 150 a removeably coupled to a second guide half 150 b at a seam 152. The first half of the bifurcated patient-specific alignment guide 150 a has similar features as the alignment guide 100 shown in FIGS. 1 and 3, such as a plurality of apertures 110, 116, 120 for guiding a plurality of pins 124 to the tibia 104. Optionally, the second half of the guide 150 b can also have a plurality of apertures 110′, 116′, and 120′ for guiding pins 124 to the tibia 104. The bifurcated guide 150 has at least one bone-engaging surface 154 that nests with and conforms to a boney structure. The boney structure can be a structure on the tibia 104 or on the fibula 105. In other embodiments, the bifurcated guide 150 has at least one soft tissue engaging surface 156 that either nests with and conforms to or provides clearance for at least one soft tissue, such as a soft tissue selected from the group consisting of the patient's MCL 113, LCL 115, patellar tendon 111, and combinations thereof. In yet other embodiments, the bifurcated guide 150 has both at least one bone-engaging surface 154 and at least one soft tissue-engaging surface 156. The second guide half 150 b allows for the guide 150 to nest with and conform to more boney structures and/or soft tissue structures than a guide that does not comprise two halves. After the pins 124 have been positioned into the tibia 104, the bifurcated guide 150 can be separated at the seam 152, which permits both the first half 150 a and the second half 150 b to slide over the pins 124 and away from the tibia 104. With reference to FIG. 6A, the present technology provides a patient-specific implant or wedge 200 a that is configured during a pre-operative planning stage of a tibial tubercle osteotomy to be wedged in a gap generated from a resection guided by the patient-specific guide 100 to maintain the position of a patient's tibial tubercle 108 relative to the tibia 104. The patient-specific implant 200 comprises a first portion 202 that has a first surface 204 that corresponds to the line 112 shown in FIG. 1. Because the first surface 204 corresponds to the line 112, the implant 200 a is custom designed to fit in a gap generated from a resection guided by the patient specific guide 100. In some embodiments, the implant 200 a further comprises an optional second portion 206 that has a second surface 208 that corresponds to the line 118 shown in FIG. 1. Because the first surface 204 corresponds to the line 112, and because the second surface 208 corresponds to the line 118, the implant 200 a with first and second portions 202, 206 is custom designed to fit in a gap generated from a resection guided by the patient specific guide 100. In yet other embodiments, the implant 200 a further comprises an optional third portion 210 that has a third surface 212 that corresponds to the line 122 shown in FIG. 1. Because the first surface 204 corresponds to the line 112, the second surface 208 corresponds to the line 118, and the third surface 212 corresponds to the line 122, the implant 200 a with first, second and third portions 202, 206, 210 is custom designed to fit in a gap generated from a resection guide by the patient specific guide 100. The patient-specific implant can be composed of a material that promotes bone in-growth. FIG. 6B is a second patient-specific implant 200 b that is similar to the implant 200 a. However, the second implant 200 b further comprises a substantially spherical portion 214 coupled to the first portion 202. The spherical portion 214 is designed to fit in a hinge bore or a stress relief hole, as described further below.

With reference to FIG. 1, the present technology provides a method for performing a tibial tubercle osteotomy on a patient's tibia 104 with the patient-specific alignment guide 100. The method comprises positioning the patient-specific guide 100 on the patient's tibia 104 at, near, or around the tubercle 108, wherein the guide 100 comprises a guide body 102 defining a portion with a bone-engaging surface configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of the patient's tibia 104, and a first plurality of apertures 110 along line 112. As described above, in some embodiments, the guide body 102 further defines a second plurality of apertures 116 along line 118 and a third plurality of apertures 120 along line 122. Accordingly, the apertures 110, 116, 120 are positioned in three intersecting straight lines 112, 118, 122 that define three predetermined angles 81, 82, 83 relative to a proximal-distal axis 114 of the patient's tibia 104 that are selected during the pre-operative planning stage of the tibial osteotomy. The guide 100 is custom made to mate with and conform to the specific patient's tibia 104, at a proximal end 106 at or near the tubercle 108. The method also includes inserting a plurality of pins 124 through the first plurality of apertures 110, and into the optional second and third plurality of apertures 116, 120, and into the patient's tibia 104. FIG. 3 shows the guide 100 positioned on the specific-patient's tibia 104, wherein pins 124 10 have been placed through the first, second, and third plurality of apertures 110, 116, 120 and into the tibia 104.

After the pins 124 have been inserted into the tibia 104, the method comprises removing the guide 100 from the tibia 104. Because the diameter D₁ of the apertures 110, 116, 120 is larger than the diameter D₂ of the pins 124, the guide 100 can be removed by simply sliding the guide 100 over the pines 124.

With reference to FIG. 4, when the pins 124 are inserted into the tibia 104, and the guide 100 has been removed, the method comprises resecting a first plane 126 into the tibia 104 adjacent to the pins 124 that are in line with the first line 112. Optionally, a bore, such as a hinge bore or a stress relief hole, can be drilled into the tibia 104 adjacent to the most distal pin 124, wherein the first plane 126 is resected from the bore to the most proximal pin 124 adjacent to the first line 112. Therefore, the pins 124 provide a saw guide for resecting the first plane 126 in the tibia 104 adjacent to the pins 124, from pin 124 to pin 124. Likewise, resecting further comprises resecting a second plane 128 into the tibia 104 adjacent to the pins 124 that are in line with the second line 118, and resecting a third plane 130 into the tibia 104 adjacent to the pins 124 that are in line with the third line 122. Resecting is performed, for example, with an oscillating saw. When all three planes 126, 128, 130 have been resected, a tubercle flap 132 is generated. Accordingly, the planes 126, 128, 130 resected into the tibia 104 are adjacent to and match the lines 112, 118, 122 configured during the preoperative planning stage.

As shown in FIG. 5, after resecting, the method comprises removing the pins 124 from the tibia 104. When the pins 124 are removed, holes 134 remain in the tibia 104. After the tubercle flap 132 has been generated, the method comprises repositioning the tubercle flap 132 in an anterior direction or in both anterior and medial-lateral directions to form a gap 136 between the tubercle flap 132 and the and three resected surfaces 138, 140, 142 of the tibia 138. Repositioning the tubercle flap 132 alters the position of the patient's patella to remove a pain-causing load and results in alleviation of a patellofemoral condition characterized by malalignment of the patella relative to asymptomatic individuals. The tubercle flap 132 is repositioned to a location predetermined during the pre-operative planning stage. After repositioning the tubercle flap 132 the method comprises implanting or positioning a patient specific implant or wedge 200 a implant gap 136, as shown in FIGS. 6A and 7. In embodiments where a hinge bore or a stress relief is drilled into the tibia 104, the implant or wedge 200 b shown in FIG. 6B is utilized. As described above, the patient-specific implant 200 a has a predetermined shape configured during the pre-operative planning stage. The implant 200 a comprises a first portion 202, and optionally a second portion 206 or a second 206 and third portion 210. In some embodiments, the patient-specific implant is composes of a material that promote bone in-growth. In an alternative method, the implant is an off-the-shelf, i.e., non-patient-specific, implantable wedge. Optionally, the method comprises securing the tubercle flap 132 by driving a screw through the tubercle flap 132 and the wedge 200 a, and into the tibia 104 through one of the resected surfaces 138, 140, 142. The wedge 200 a maintains the position of the repositioned tubercle flap 132 and prevents the tubercle flap 132 from reverting to its original location.

The current technology provides another patient-specific tibial osteotomy guide 300 as shown in FIG. 8. The guide 300 comprises a guide body 302 that defines a portion with a bone-engaging surface 303 configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's tibia 104. As shown in FIG. 8, the guide 300 is positioned on the specific patient's tibia 104 about a tubercle 108 on a medial face of the tibia 104. In other embodiments, the guide 300 can be configured to be positioned on a lateral face of the specific patient's tibia 104. The bone engaging surface 303 is custom made during the preoperative planning stage to match a specific patient's anatomy and allows for placement of the guide 300 at a specific location, and in only one position, at a proximal portion 106 of the patient's tibia 104. Typically, the guide 300 is configured to fit on a specific patient's tibia 104 at, around, or near the tubercle 108, which is to be repositioned during an osteotomy.

In some embodiments, the guide body 302 also defines a soft tissue-clearing portion 309 that allows for clearance of soft tissue, such as ligaments and tendons. The soft tissue-clearing portion 309 has an outer convex surface and an inner concave surface, wherein the inner concave surface provides a recess for accommodating soft tissue. As shown in FIG. 8, the soft tissue-clearing portion 309 accommodates the patient's patellar tendon 111. However, in various embodiments, the tissue-clearing portion 309 accommodates a medial collateral ligament (MCL) 113 or a lateral cruciate ligament (LCL, not shown). In this regard, the bone-engaging surface 303 mates with and conforms to a specific boney region of the tibia 104, and the patellar soft tissue-clearing portion 309 allows for the guide to simultaneously be placed about the patient's soft tissue, such as the patellar tendon 111. In other embodiments, the guide 300 comprises a plurality of tissue-clearing portions 309 for simultaneously accommodating the LCL and patellar tendon, or MCL and patellar tendon.

In additional embodiments, the guide body 302 further defines a soft tissue engaging surface 309′, wherein the soft tissue-engaging surface 309′ is configured during the pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's soft tissue at, around, or near the tubercle 108. The soft tissue can be, for example, the patient's MCL, LCL, or patellar tendon. In various embodiments, the guide 300 comprises a plurality of soft tissue engaging surfaces 309′ for simultaneously accommodating the LCL and patellar tendon, or MCL and patellar tendon. In other embodiments, the guide 300 has both a soft tissue-clearing portion 309 and a soft tissue engaging surface 309′.

The guide body 302 further defines a first planar slot 304 positioned along a fourth straight line 306 that defines a fourth predetermined angle 84 relative to a proximal-distal axis 114 of the specific patient's tibia 104. The fourth straight line 306 is selected during the pre-operative planning stage of the tibial osteotomy. Therefore, the first planar slot 304 is oriented at a fourth predetermined angle 84 and at a first predetermined position relative to a proximal-distal axis 114 of the specific patient's tibia 104 that is selected during the pre-operative planning stage of the tibial osteotomy. The first planar slot 304 defined by the guide body 302 has a distal end 308 and a proximal end 310, wherein the guide body 302 further defines a circular slot 312 in communication with the first distal end 308.

Additionally, the guide body 302 defines a second planar slot 314 positioned along a fifth straight line 316 that defines a fifth predetermined angle θ₅ relative to a proximal-distal axis 114 of the specific patient's tibia 104. The fifth straight line 316 is selected during the pre-operative planning stage of the tibial osteotomy. Therefore, the second planar slot 314 is oriented at a fifth predetermined angle θ₅ and at a second predetermined position relative to a proximal-distal axis 114 of the specific patient's tibia 104 that is selected during the pre-operative planning stage of the tibial osteotomy

Additionally, the guide body 302 defines a third planar slot 315 positioned along a fifth straight line 317 that defines a sixth predetermined angle θ₆ relative to a proximal-distal axis 114 of the specific patient's tibia 104. The sixth straight line 317 is selected during the pre-operative planning stage of the tibial osteotomy. Therefore, the third planar slot 315 is oriented at a sixth predetermined angle θ₆ and at a third predetermined position relative to a proximal-distal axis 114 of the specific patient's tibia 104 that is selected during the pre-operative planning stage of the tibial osteotomy

The guide body 302 of the patient specific guide 300 also defines a plurality of apertures 318 for removeably anchoring the guide 300 to the specific patient's tibia 104. The apertures have a diameter D₃ and the pins have a diameter D₄, wherein D₃ is smaller than D₄. Because the apertures 318 have a smaller diameter than the pins 320, the guide 300 can be attached to the tibia 104 by way inserting the pins 320 through the apertures 318 and into the tibia 104. To remove the guide 300 from the tibia 104, the pins 320 must first be removed.

The present technology also provides a method for performing a tibial tubercle osteotomy on a patient's tibia with the use of the patient-specific guide 300. As shown in FIG. 8, the method comprises anchoring the guide 300 to the patient's tibia 104 by inserting pins 320 through the apertures 318 and into the tibia 104. When the guide 300 is anchored in place, the method comprises inserting a drill bit through the circular slot 312 and drilling a circular hinge bore or stress relief hole 322 through the tibia 104.

After drilling, the method comprises inserting a saw blade through the first slot 304 and resecting a first plane 324 from the bore 322 to the proximal end 310 of the first slot 304. Likewise, the method comprises inserting the saw blade through the second slot 314 and resecting a second plane 326 and inserting the saw blade through the third slot 315 and resecting a third plane 328. Resecting can be performed, for example, with an oscillating saw. After the planes 324, 326, 328 have been resected through the tibia 104 via the slots 304, 314, 315 in the guide 300, the method comprises removing the pins 320 from the tibia 104, which exposes pin holes 321, and subsequently removing the guide 300. As shown in FIG. 9, after the guide 300 has been removed, the method comprises resecting the tibia 104 to connect the first plane 324 to the second plane 326, the second plane 326 to the third plane 328, and the third plane 328 to an anterior surface of the tibia 104 proximal to the tubercle 108 to form a tubercle flap 330 adjacent to a resected surface of the tibia.

As shown in FIG. 10, after the tubercle flap 330 has been generated, the method comprises repositioning the tubercle flap 330 in an anterior direction or in both anterior and medial-lateral directions to form a gap 338 between the tubercle flap 330 and three resected surfaces 332, 334, 336 of the tibia 104. The hinge bore or stress relief hole 322 ensures that repositioning the tubercle flap 330 does not crack or splinter the tibia 104. The tubercle flap 330 is repositioned to a location predetermined during the pre-operative planning stage. Repositioning the tubercle flap 132 alters the position of the patient's patella remove a pain-causing load and results in alleviation of a patellofemoral condition characterized by malalignment of the patella relative to asymptomatic individuals. After repositioning the tubercle flap 330 the method comprises implanting or positioning a patient specific implant or wedge 200 a, 200 b in gap 338, as shown in FIGS. 6A, 6B, and 11. As described above, the patient-specific implant 200 a, 200 b has a predetermined shape configured during the preoperative planning stage. The implant 200 a, 200 b comprises a first portion 202, and optionally a second portion 206 or a second 206 and third portion 210. In some embodiments, the patient-specific implant 200 a, 200 b is composed of a material that promotes bone in-growth. When the second implant 200 b is used, the spherical portion 214 is positioned in the stress relief hole 322. In an alternative method, the implant is an off-the-shelf, i.e., non-patient-specific, implantable wedge. Optionally, the method comprises securing the tubercle flap 330 by driving a screw 340 through the tubercle flap 330 and the wedge 200 a, 200 b, and into the tibia 104 through one of the resected surface 332. The wedge 200 a, 200 b maintains the position of the repositioned tubercle flap 330 relative to the tibia 104 and prevents the tubercle flap 330 from reverting to its original location.

The present technology additionally provides for a surgical kit or a system for a tibial osteotomy comprising a patient-specific guide comprising a guide body defining a portion with a bone-engaging surface that conforms as a negative surface to a corresponding surface of a specific patient's tibia, and a guide portion that guides a surgical instrument to a specific location on the specific patient's tibia, wherein the bone-engaging surface and guide portion are configured during a pre-operative planning stage; a patient-specific implantable wedge with a predetermined shape, wherein the wedge is configured during the pre-operative planning stage; and a plurality of pins.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. 

What is claimed is:
 1. A patient-specific system for a tibial osteotomy, comprising: a patient-specific guide comprising a guide body defining, a bone-engaging portion with a bone-engaging surface, wherein the bone-engaging surface is configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's tibia at, around, or near the patient's tibial tubercle; a first planar slot oriented at a first predetermined angle and at a first predetermined position relative to a proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy; a second planar slot oriented at a second predetermined angle and at a second predetermined position relative to the proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy; and a plurality of apertures.
 2. The patient-specific system according to claim 1, wherein the first planar slot defined by the guide body has a distal end and a proximal end, and wherein the guide body further defines a circular slot in communication with the first distal end.
 3. The patient-specific system according to claim 1, wherein the plurality of apertures are configured to accept pins for removeably anchoring the guide to the specific patient's tibia at a single location near the patient's tibial tubercle.
 4. The patient-specific system according to claim 1, wherein the guide body further defines a soft tissue-engaging surface, wherein the soft tissue-engaging surface is configured during the pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of a specific patient's soft tissue at or about the tubercle.
 5. The patient-specific system according to claim 4, wherein the specific patient's soft tissue is the patient's medial collateral ligament, lateral cruciate ligament, or patellar tendon.
 6. The patient-specific system according to claim 1, wherein the guide body further defines a soft tissue-clearing portion comprising an outer convex surface and an inner concave surface, wherein the inner concave surface provides a recess for accommodating the patient's medial collateral ligament, lateral cruciate ligament, or patellar tendon.
 7. A method for performing a tibial tubercle osteotomy on a patient's tibia, comprising: positioning a patient-specific guide on the patient's tibia, wherein the guide comprises a guide body defining a bone-engaging portion with a bone-engaging surface configured during a pre-operative planning stage of a tibial osteotomy to conform as a negative surface to a corresponding surface of the patient's tibia at, around or near the tubercle of the patient's tibia, and a plurality of apertures; resecting the tibia in three intersecting planes with a saw to generate a tubercle flap, wherein the patient-specific guide provides visual indicia for resecting; and repositioning the tubercle flap in an anterior direction or in both anterior and medial-lateral directions to form a gap between the tubercle flap and the resected surface of the tibia.
 8. The method according to claim 7, further comprising implanting a wedge in the gap, wherein the wedge has a predetermined shape configured during the pre-operative planning stage and wherein the wedge is composed of a material that promotes bone in-growth.
 9. The method according to claim 8, further comprising securing the tubercle flap relative to the resected surface of the tibia by driving a screw through the tubercle flap and the wedge, and into the tibia through the resected surface.
 10. The method according to claim 7, wherein the plurality of apertures are positioned along three intersecting lines that define three predetermined angles relative to a proximal-distal axis of the patient's tibia that are selected during the pre-operative planning stage of the tibial osteotomy, and wherein the method further comprises: inserting a plurality of pins through the apertures, the pins having a diameter smaller than a diameter of the apertures; and removing the patient specific guide, wherein the pins provide the visual indicia for resecting.
 11. The method according to claim 7, wherein the guide body further defines a first planar slot oriented at a first predetermined angle and at a first predetermined position relative to a proximal-distal axis of the specific patient's tibia that is selected during the pre-operative planning stage of the tibial osteotomy, wherein the first planar slot defined by the guide body has a distal end and a proximal end, the guide body further defining a circular slot in communication with the first distal end, and wherein the method further comprises: anchoring the guide to the patient's tibia near the tubercle by inserting pins through the apertures and into the tibia; inserting a drill bit through the circular slot and drilling a hole through the tibia; resecting a first plane through the tibia by inserting a saw blade through the first slot; resecting a second plane through the tibia by inserting a saw blade through the second slot; removing the pins and the guide; further resecting the tibia to connect the first plane and the second plane; and resecting a third plane through the tibia to connect the second plane to an anterior surface of the tibia to form the tubercle flap.
 12. The method according to claim 7, wherein the guide body further defines a soft tissue-clearing portion comprising an outer convex surface and an inner concave surface, and wherein positioning the patient-specific guide on the patient's tibia further comprises nesting the bone-engaging surface of the guide onto a corresponding surface on the tibia, wherein the inner concave surface of the soft tissue-clearing portion provides a recess for accommodating the patient's medial collateral ligament, lateral cruciate ligament, or patellar tendon. 